After much back and forth, I then decided to use the Nano and I'm frankly very impressed by the small box.
The image quality is both in HD and SD area very well, the switching times are pleasantly short and smart features I find super integrated. The recording function to an external USB drive works fine, but I would have liked a few additional desired programming functions in the EPG (eg all episodes of the series automatically record).
For the small all-rounder, the price / performance ratio is is outstanding.
Highly recommended!